Illuminated keyboard

ABSTRACT

An illuminated keyboard. The illuminated keyboard comprises a key switch, a backlight device, a light-condensing plate, a diffuser, a printed circuit board, and a light source. The key switch includes a seat and a cap, and the cap is disposed on the seat in a moveable manner. The backlight device is disposed beneath the key switch to illuminate the key switch. The light-condensing plate is disposed between the light guide and the key switch. The diffuser is disposed between the light guide and the key switch. The printed circuit board is disposed between the seat and the backlight device. The light source is disposed on the printed circuit board.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to an illuminated keyboard; in particular,an illuminated keyboard with improved illumination capability.

[0003] 2. Description of the Related Art

[0004] Since computers may be used in various environments, such as darkenvironments, an illuminated keyboard has been provided.

[0005]FIG. 1 is a schematic view of a conventional illuminated keyboard10 as disclosed in U.S. Pat. No. 6,284,988. The illuminated keyboard 10comprises a key switch 11, and a backlight device 15 disposed in the keyswitch 11. Specifically, the key switch 11 comprises a seat 111, aprinted circuit board 112, an elastic member 113 a, a cap 114, and aconnecting assembly 115. The printed circuit board 112 is disposed onthe seat 111. The elastic member 113 a is formed on the printed circuitboard 112. The cap 114 corresponds to the elastic member 113 a. One endof the connecting assembly 115 is connected to fixed members 111 a ofthe seat 111 in a slideable and rotatable manner, and the other end ofthe connecting assembly 115 is connected to the cap 114. Thus, the cap114 can move upward and downward relative to the seat 111. The backlightdevice 15 is an electroluminescent device.

[0006] In the conventional illuminated keyboard 10, since the backlightdevice 15 is disposed on the printed circuit board 112 of the key switch11, the backlight device 15 is provided with a through hole 151 so thatthe cap 114 can connect to the seat 111 via the connecting assembly 115.For the same reason, the printed circuit board 112 is also provided witha through hole (not shown). As a result, manufacture of the conventionalilluminated keyboard is complicated, and the illumination capability ofthe conventional illuminated keyboard is limited.

SUMMARY OF THE INVENTION

[0007] In order to address the disadvantages of the aforementionedilluminated keyboard, the invention provides an illuminated keyboardwith improved illumination capability.

[0008] Accordingly, the invention provides an illuminated keyboard. Theilluminated keyboard comprises a key switch and a backlight device. Thekey switch includes a seat and a cap, the cap is disposed on the seat ina moveable manner. The backlight device is disposed beneath the keyswitch to illuminate the key switch.

[0009] In a preferred embodiment, the seat includes a first through holecorresponding to the cap.

[0010] Furthermore, the first through hole is filled with a transparentmaterial.

[0011] In another preferred embodiment, the backlight device is anelectroluminescent sheet.

[0012] In another preferred embodiment, the backlight device comprises aplate, a plurality of optical fibers, and a light source. The plate isdisposed beneath the key switch. The light fibers are disposed on theplate. The light source is connected to the optical fibers.

[0013] In another preferred embodiment, the key switch further comprisesa plastic membrane, and the plastic membrane includes an elastic member.

[0014] Furthermore, the plastic membrane is of a light-condensingmaterial or a light-diffusing material.

[0015] In another preferred embodiment, the backlight device comprises alight guide and a light source. The light guide, including a reflectiveportion, is disposed beneath the key switch. The light source isdisposed adjacent to the light guide.

[0016] Furthermore, the reflective portion is a reflector plate disposedbeneath the light guide or a rough surface integrally formed at a bottomof the light guide or a reflective surface printed at a bottom of thelight guide.

[0017] Furthermore, the illuminated keyboard further comprises alight-condensing plate and a diffuser. The light-condensing is plate isdisposed between the light guide and the key switch. The diffuser isdisposed between the light guide and the key switch.

[0018] In another preferred embodiment, the illuminated keyboard furthercomprises a printed circuit board and a light source. The printedcircuit board is disposed between the seat and the cap. The light sourceis disposed on the printed circuit board.

[0019] In another preferred embodiment, the illuminated keyboard furthercomprises a printed circuit board and a light source. The printedcircuit board is disposed between the seat and the backlight device. Thelight source is disposed on the printed circuit board.

[0020] Furthermore, the seat includes a second through hole, and thelight source passes through the second through hole.

[0021] Furthermore, the light source is an LED.

[0022] Furthermore, the printed circuit board is of a light-condensingmaterial or a light-diffusing material.

[0023] In another preferred embodiment, the illuminated keyboardcomprises a light guide, a cap, a connecting assembly, a light source,and a printed circuit board. The light guide includes a plurality offixed members. The cap is disposed on the light guide. The connectingassembly connects the fixed members and the cap to move the cap relativeto the light guide. The light source is disposed adjacent to the lightguide to provide a light to the light guide and illuminate theilluminated keyboard. The printed circuit board, disposed between thelight guide and the cap, is electrically coupled to the light source.

[0024] Furthermore, the light guide includes a concave portion, and thelight source is disposed in the concave portion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The invention is hereinafter described in detail with referenceto the accompanying drawings in which:

[0026]FIG. 1 is a schematic view of a conventional illuminated keyboard;

[0027]FIG. 2 is a schematic view of an illuminated keyboard as disclosedin this invention;

[0028]FIG. 3 is a cross section of the assembled illuminated keyboard inFIG. 2;

[0029]FIG. 4a is a cross section of the assembled illuminated keyboard,wherein a backlight device is a variant embodiment;

[0030]FIG. 4b is a cross section of the assembled illuminated keyboard,wherein a backlight device is another variant embodiment;

[0031]FIG. 5a is a schematic view of the assembled illuminated keyboardin FIG. 2;

[0032]FIG. 5b is a cross section along line A-A in FIG. 5a;

[0033]FIG. 5c is a schematic view of a variant embodiment of anilluminated keyboard as disclosed in this invention, wherein a lightsource is a variant embodiment;

[0034]FIG. 5d is a cross section along line B-B in FIG. 5c;

[0035]FIG. 5e is a partial enlarged view in FIG. 5d;

[0036]FIG. 6 is a schematic view of another variant embodiment of anilluminated keyboard as disclosed in this invention; and

[0037]FIG. 7 is a schematic view that shows another variant embodimentof the backlight device.

DETAILED DESCRIPTION OF THE INVENTION

[0038]FIG. 2 is a schematic view of an illuminated keyboard 20 asdisclosed in this invention. As shown in FIG. 2, the illuminatedkeyboard 20 comprises a key switch 22 and a backlight device 23. It isnoted that the illuminated keyboard 20 further comprises a housing, acover, and other elements of a conventional keyboard. However, forsimplicity, such elements are omitted.

[0039] The key switch 22 is disposed on the housing (not shown) of theilluminated keyboard 20, and comprise a seat 222, a membrane circuitboard 223, a cap 224, an elastic member 221, and a connecting assembly225. Referring to FIG. 3, the seat is provided with a plurality of fixedmembers 2221. One end of the connecting assembly 225 is connected tofixed members 2221 of the seat 222 in a slideable and rotatable manner,and the other end of the connecting assembly 225 is connected to the cap224. Thus, the cap 224 can move upward and downward relative to the seat222. The elastic member 221 is disposed between the membrane circuitboard 223 and the cap 224 to support the cap 224.

[0040] The seat 222 includes a first through hole 2222 corresponding tothe elastic member 221. It is understood that the first through hole2222 can be filled with an intermediate layer 226 of transparentmaterial.

[0041] The membrane circuit board 223 may be transparent plastic, suchas PE (polyester). In addition, the elastic member 221 may be formed onMylar 221 a to increase convenience of assembly of the keyboard 20, orthe elastic member 221 may be directly mounted on the membrane circuitboard 223. If there is no intermediate layer 226 in the first throughhole 2222, the thickness of the membrane circuit board 223 increases.

[0042] Referring to FIG. 2, the backlight device 23 is disposed beneaththe key switch 22 to illuminate the key switch 22 from the bottom of thekey switch 22. The backlight device 23 comprises a light guide 231, areflector plate 232 and a light source 233.

[0043] As shown in FIG. 2, the light guide 231 includes a plurality ofreflective portions 231 a at the bottom surface, and is disposed beneaththe seat 222 of the key switch 22. The reflective portions 231 a arelocated under the intermediate layer 226, and reflect a light, emittedfrom the light source 233, to the key switch 22 to enhance illuminationcapability. The reflective portions 231 a may be printed at the bottomsurface of the light guide 231, or are integrally formed on a roughsurface at the bottom of the light guide 231. It is noted that the areaof the reflective portions 231 a becomes smaller when they are near thelight source 233, and larger when they are far away from the lightsource 233.

[0044] In addition, the light guide 231 may be integrally formed withseat 222 to reduce the thickness of the whole keyboard 20. Specifically,the seat 222 of the key switch 22 is of light-guiding material, and thefixed members 2221 are formed on the seat 222 by injection molding. Forexample, the light-guiding material may be Acrylic, or polycarbonate(PC), or ABS.

[0045] Referring to FIG. 4a, the illuminated keyboard 20 may furthercomprise a light-condensing plate 234 and a diffuser 235. Thelight-condensing plate 234 is disposed between the light guide 231 andthe key switch 22. The diffuser is also disposed between the light guide231 and the key switch 22. The light-condensing plate 234 may be PCmembrane, and the diffuser 235 may be PET membrane.

[0046] For reducing the thickness of the whole keyboard 20, the elasticmember 221 may be connected to the diffuser 235, the diffuser 235disposed between the light guide 231 and the cap 224, and thelight-condensing plate 234 may be integrally formed with the membranecircuit board 223, as shown in FIG. 4b. In addition, the elastic member221 may be transparent rubber, connected to the diffuser 235 to attainthe light-diffusing effect.

[0047] It is understood that the elastic member may be formed on thelight-condensing plate to remove the diffuser, or the membrane circuitboard may be integrally formed with the diffuser to remove thelight-condensing plate.

[0048] Referring to FIG. 3, FIG. 5a, and FIG. 5b, the light source 233is disposed on the membrane circuit board 223 in a manner such that itis located adjacent to the light guide 231. A shielding member 236 isdisposed adjacent to the light source 233 so that the light, emittedfrom the light source 233, can be fully directed to the light guide 231.In addition, the light source 233 can be disposed on the membranecircuit board 223 via the shielding member 236 so that no additionalmounting member for the light source 233 is required.

[0049] Referring to FIG. 5c, FIG. 5d, and FIG. 5e, the light guide 231may be provided with a plurality of concave portions 231 b, and the seat222 is provided with a plurality of second through holes 222 acorresponding to the concave portions 231 b. Thus, the light source 233is disposed beneath the membrane circuit board 223, and it located inthe concave portion 231 b through the second through hole 222 a. As aresult, the illumination capability of the illuminated keyboard 20 canbe enhanced.

[0050] It is understood that the light source 233 may be an LED.

[0051] Referring to FIG. 2, the reflector plate 232 is disposed beneaththe light guide 231 to reflect the light, emitted from the light source233, to the key switch 22. It is understood that the reflector plate 232can be removed if the light guide 231 is provided with the reflectiveportions 231 a at the bottom surface as stated above.

[0052]FIG. 6 is a schematic view of a variant embodiment of anilluminated keyboard as disclosed in this invention. In this embodiment,the backlight device is an electroluminescent sheet (EL sheet) 240. TheEL sheet 240 is electrically coupled to the membrane circuit board 223or a power source (not shown) of the keyboard 20.

[0053]FIG. 7 is a schematic view of another variant embodiment of anilluminated keyboard as disclosed in this invention. In this embodiment,the backlight device 25 comprises a plate 251, a plurality of opticalfibers 250, and a light source 252. The plate 251 is disposed beneaththe key switch 22. The light fibers 250 are disposed on the plate 251.The light source 252 is electrically coupled to a power source (notshown) of the keyboard 20, and is located adjacent to the optical fibers250 to illuminate the keyboard 20.

[0054] Alternatively, the membrane circuit board 223 may be disposedbeneath the seat 222, with the elastic member 221 disposed on themembrane circuit board 223 and passing through the seat 222 to supportthe cap 224. Furthermore, the elastic member 221 may be disposed on theseat 222 so that the elastic member 221 is in contact with a switch (notshown) on the membrane circuit board 223 to generate a correspondingsignal when the cap 224 is pressed down.

[0055] The advantages of the illuminated keyboard 20 are described asfollows.

[0056] 1. Since the backlight device is disposed beneath the key switch,the light guide is not provided with a through hole like the printedcircuit board. Thus, manufacture is simplified, and the illuminationcapability is improved.

[0057] 2. Since the light source is disposed on the membrane circuitboard, it is not necessary to add members for mounting the light source.In addition, since the light source can be located in the concaveportion of the light guide, the illumination capability of the keyboardcan be enhanced.

[0058] 3. The seat may be light-guiding material, the elastic member maybe connected to the diffuser or the light-condensing plate, and themembrane circuit board may be light-condensing material; therefore, thethickness of the whole illuminated keyboard can be decreased.

[0059] 4. Since the seat is provided with through holes corresponding tothe elastic members, the weight of the whole illuminated keyboard can bereduced.

[0060] While the invention has been particularly shown and describedwith reference to a preferred embodiment, it will be readily appreciatedby those of ordinary skill in the art that various changes andmodifications may be made without departing from the spirit and scope ofthe invention. It is intended that the claims be interpreted to coverthe disclosed embodiment, those alternatives which have been discussedabove, and all equivalents thereto.

What is claimed is:
 1. An illuminated keyboard comprising: a key switchincluding a seat and a cap, wherein the cap is disposed on the seat in amoveable manner; and a backlight device disposed beneath the key switchto illuminate the key switch.
 2. The illuminated keyboard as claimed inclaim 1, wherein the seat includes a first through hole corresponding tothe cap.
 3. The illuminated keyboard as claimed in claim 2, wherein thefirst through hole is filled with a transparent material.
 4. Theilluminated keyboard as claimed in claim 1, wherein the backlight deviceis an electroluminescent sheet.
 5. The illuminated keyboard as claimedin claim 1, wherein the backlight device comprises: a plate disposedbeneath the key switch; a plurality of optical fibers disposed on theplate; and a light source disposed adjacent to the optical fibers. 6.The illuminated keyboard as claimed in claim 1, wherein the key switchfurther comprises a plastic membrane, and the plastic membrane includesan elastic member.
 7. The illuminated keyboard as claimed in claim 6,wherein the plastic membrane is of a light-condensing material.
 8. Theilluminated keyboard as claimed in claim 6, wherein the plastic membraneis of a light-diffusing material.
 9. The illuminated keyboard as claimedin claim 1, wherein the backlight device comprises: a light guide,including a reflective portion, disposed beneath the key switch; and alight source disposed adjacent to the light guide.
 10. The illuminatedkeyboard as claimed in claim 9, wherein the reflective portion is areflector plate disposed beneath the light guide.
 11. The illuminatedkeyboard as claimed in claim 9, wherein the reflective portion is arough surface integrally formed at a bottom of the light guide.
 12. Theilluminated keyboard as claimed in claim 9, wherein the reflectiveportion is a reflective surface printed at a bottom of the light guide.13. The illuminated keyboard as claimed in claim 9, further comprising:a light-condensing plate disposed between the light guide and the keyswitch.
 14. The illuminated keyboard as claimed in claim 9, furthercomprising: a diffuser disposed between the light guide and the keyswitch.
 15. The illuminated keyboard as claimed in claim 1, furthercomprising: a printed circuit board disposed between the seat and thecap; and a light source disposed on the printed circuit board.
 16. Theilluminated keyboard as claimed in claim 1, further comprising: aprinted circuit board disposed between the seat and the backlightdevice; and a light source disposed on the printed circuit board. 17.The illuminated keyboard as claimed in claim 16, wherein the seatincludes a second through hole, and the light source passes through thesecond through hole.
 18. The illuminated keyboard as claimed in claim16, wherein the light source is an LED.
 19. The illuminated keyboard asclaimed in claim 16, wherein the printed circuit board is of alight-condensing material.
 20. The illuminated keyboard as claimed inclaim 16, wherein the printed circuit board is of a light-diffusingmaterial.
 21. An illuminated keyboard comprising: a light guideincluding a plurality of fixed members; a cap disposed on the lightguide; a connecting assembly connecting the fixed members and the cap tomove the cap relative to the light guide; and a light source disposedadjacent to the light guide to provide a light to the light guide andilluminate the illuminated keyboard.
 22. The illuminated keyboard asclaimed in claim 21, further comprising: a printed circuit board,disposed between the light guide and the cap, electrically coupled tothe light source.
 23. The illuminated keyboard as claimed in claim 21,wherein the light guide includes a concave portion, and the light sourceis disposed in the concave portion.
 24. The illuminated keyboard asclaimed in claim 23, further comprising: a printed circuit boardelectrically coupled to the light source.